Objective: To investigate he efficacy and the mechanism of Chaihu Jia Longgu Muli Tang (TJ-12) on posttraumatic stress disorder. Method: ICR mice and EL mice were used to establish the social defeat stress (SS) model. The animals were divided into five groups:TJ-12 high

middle

low dose groups(orally given for 4 weeks

1

0.5

0.1 g·kg-1 ·d-1)

SS group and control group. Contextual fear conditioning test (CFC)was evaluated

and mRNA expression of glicocorticoid receptor(GR) and brain-derived neurotrophic factor(BDNF)in the hippocampus of the animals were measured by real time RT-PCR. Result: In SS group the freezing pecent scores of CFC test were increased and the mRNA expression level of GR and BDNF in hippocampus of SS mice was also significantly higher than the controls; Compared with the SS group

freezing percent of CFC test and mRNA expression of BDNF in hippocampus were decreased in TJ-12 high

middle

low dose groups. Conclusion: TJ-12 may be effective for treating the posttraumatic stress disorder by altering the gene expression of BDNF in hippocampus.